Such apparatus conventionally comprises a jet nozzle which is secured on to the bodywork of the vehicle close to the glass to be cleaned, for example on the hood in the case where the glass is the windshield of the vehicle, the nozzle being oriented towards the glass. The nozzle is connected through a flexible feed tube to a reservoir for containing a washing liquid, and where necessary a pump is interposed between the reservoir and the nozzle for delivering the liquid to the latter. A windshield wiper, comprising an arm and a blade carried by the arm, spreads the liquid, which is projected by the nozzle, over the surface of the glass.
A drawback of this system is that all or part of the jet of liquid may be diverted, in particular by the wind, and may not ever reach the glass. In order to overcome this drawback, systems are provided in which the feed tube which supplies the washing liquid is arranged to extend along the windshield wiper arm, its terminal end being fixed to the wiper blade and orientated towards the glass in such a way as to give a direct jet of liquid which is very short and which will therefore be sure to impinge on the glass. This arrangement is however ugly in appearance, and also necessitates special fitting operations in order to ensure correct positioning of the free end of the feed tube.